Keratin materials, such as the skin, the scalp, and the hair, are continuously exposed to many hazardous environmental agents, including UV radiation, air pollutants, such as ozone and ionizing radiation, which generate Reactive Oxygen Species (ROS), among which, the exposure to the sun has caused to the keratin materials many hazardous problems, such as sunburn and aging caused by UV rays and pro-oxidants.
UVB rays, with a short wavelength and highly energy-intensive, are responsible for sunburns of the skin. UVA rays are less energy-intensive, but 20 times more numerous than UVB rays. The UV radiation can induce photoaging of the keratin materials, such as the skin, the scalp, and the hair.
Besides, the skin, the scalp and the hair are directly and frequently exposed to environmental pro-oxidants caused by the sun exposure and are particularly sensitive to the action of oxidative stress, its outermost lay serves as a barrier to oxidative damage that may occur. In most circumstances, the oxidizing agent is generally neutralized after reaction with keratin materials, but the reaction products formed may be responsible for cell and tissue damage. The stratum corneum, the skin barrier is the site of contact between air and skin tissue and structure biphasic lipid/protein is a crucial determinant of the barrier function of the skin. These elements can react with oxidants and be altered, which will help scaling phenomena.
Thus, the harmful effects of UV lights and peroxidation on the keratin materials affect cellular respiration of these keratin materials and result in accelerated aging of the skin with a dull complexion and premature formation of wrinkles and fine lines, as well as a decrease in the strength of the hair also take a dull appearance. In addition, because of the UV and the peroxidation, skin and hair gets dirty faster. In addition, the UV and the peroxidation can cause irritation and allergic phenomena and inflammation on the skin.
To fight against the UV rays and the pro-oxidants, various compositions comprising UV filters and/or anti-oxidation compounds were described. However, there still remains a need for a novel composition for protecting the keratin materials from hazardous effects caused by sun exposure, which possess desired sun protection factor (SPF) value, and an improved anti-oxidation effect, and stable over time.